Why is plant diversity important?
I can come up with lots of reasons, including the value to pollinators, correlations between plant and insect diversity, and contributions to ecological resilience – among others. But it’s much more difficult to quantify the specific functional differences between high-diversity and low-diversity prairie plantings. Even basic questions are difficult – for example, how many plant species does it take to see benefits?
Most of us who spend time in prairies know intuitively that plant diversity is important, but if we’re going to influence environmental policy, agricultural practices, and other large-scale conservation strategies, we’re going to need stronger and more quantified answers than intuition provides us.
In an attempt to help find some of those more specific answers, we have built some research plots within our Platte River Prairies, in which we’ve established prairie plantings of various plant diversity. Each treatment plot is 3/4 acre (1/3 ha) in size – big enough that we hope to compare patterns of invertebrate species composition and activity, soil changes, differences in the resistance to invasive species, and more. We’ve actually established two sets of plots now; one in 2006 and the second in 2010. The 2006 set consists of low diversity (15 species) and high diversity (100 species) plots, and the 2010 set consists of three treatments: a monoculture of big bluestem, low diversity (mostly grasses, with a few forbs), and high diversity (100 or more plant species). Each treatment is replicated at least 4 times.
To date, our research team has focused mainly on the 2006 plots, and has collected data on soils, nematodes, invertebrates, insect herbivory rates, rates of invasive species encroachment, and more. We’ve seen some intriguing patterns in terms of insect herbivory rates and invasive species encroachment, but have more work to do. This year we’ll start to collect our first data on the 2010 plots as well. So far, we’ve had researchers from the University of Nebraska-Lincoln, the Nebraska Cooperative Fish and Wildlife Research Unit, Simpson College, and Kansas State University. Several research papers have already been submitted to journals, and more are on the way. We’d love to add more researchers to the project, so please let me know if you’re interested in participating. We’re also looking for a PhD student or two to work on the project (see our earlier announcement).
Here are a few photos from last week, showing what the plant communities in the research plots look like:
I have lots of research questions I’d like to explore with these plots, but I’m curious to hear what questions come to mind for you. Are there challenges you’re dealing with or issues you know of that we could help address by designing our research in a particular way? Or are there questions you’d ask just because you’re curious? I’d love to hear suggestions, and I’ll pass them on to the others working at the site.